Different ways of controlling the output pulse duration and pulse shape in Nd:YAG lasers with SBS-mirrors

Summary form only given. Currently a common laser scheme includes a master oscillator, a multipass laser amplifier and a stimulated Brillouin scattering (SBS) mirror. An important feature of such lasers is shortening of the output pulse duration and change of the output pulse shape under a combined action of two nonlinear processes: SBS and amplification. Due to the nonstationarity of SBS near threshold, an intensity jump occurs at the leading edge of a Stokes pulse, while due to the nonlinearity of amplification, this intensity jump becomes essential in formation of an output pulse. In the present work, different ways of controlling output pulse shape and output pulse duration are suggested and realized in experiment. These ways are based on the attenuation of a beam between a SBS-mirror and an amplifier. This attenuation can reduce the jump of a Stokes pulse and, consequently, increase the output pulse duration. The output pulse energy loss may appear to be insignificant if the amplifier operates in the regime of saturation.